STK Aircraft Mission Modeler

1. STK Aircraft Mission Modeler Tom Neely

2. Introduction About the author and inventor – Tom Neely • F-14 Tomcat Radar Intercept Officer • 850 flight hours • 170+ carrier arrested landings • US Naval Postgraduate School • Aerospace Engineering • Electrical Engineering • Analytical Graphics • Development project leader • Author of STK/Radar and STK/Matlab

3. Agenda • Intro to Aircraft Mission Modeler • What is Aircraft Mission Modeler? • Rapid mission modeling in 3D • Terrain following • Detailed Mission Modeling • Sites & procedures • Performance Models • Phases • Catalogs • Under the hood

4. Aircraft Mission Modeler • New aircraft object propagator • Significantly enhanced over great arc aircraft • Based on aircraft performance characteristics • Airspeed • Climb rate • Roll rate • Bank angle • Aircraft types • Pre-defined • Customizable

5. Aircraft Mission Modeler (cont.) • Quickly create fundamental mission models • 3D Editing • One-click maneuvers • Smart aircraft performance defaults • Numerous models • Catalogs • Ability to design advanced mission models • Aircraft models • Build complex, multi-segment mission models

6. 3D editing • Inserting a site • Procedure control points • Move, rotate and stretch holding patterns • Alter heading and climb angle at a waypoint • Move waypoint/runway

7. Aircraft • Defined by a family of performance models • Performance model categories in STK 7.0: • Climb • Cruise • Descend • Accelerate (turn) • Takeoff • Land • Terrain Following

8. Aircraft (cont.) • Contain default performance models • Users can design new performance models • Procedures and performance define flight path • Aircraft and performance models are extensible

9. Sites • Waypoints and runways • Every procedure refers to a site • Sites constrain the type of procedure • Sites can be saved to a catalog • Sites are extensible

10. Procedures • Procedure types included in STK 7 • Takeoff and landing • Various point-to-point • Various holding • Architecture is extensible

11. Mission modeling • Aircraft with defined performance models • One or more phases • Use specific performance models for each phase • Each phase has procedures • A procedure refers to a site • Sites constrain procedure types

12. Mission Modeler UI • Supports rapid setup • Aircraft-specific performance • Combines procedures • Takeoff • Enroute • Arc • Acceleration (turn) • Holding patterns • Landing • Configurable, graphical feedback

13. Aircraft performance models • User-configurable aircraft models • Unlimited number of performance models per aircraft • Linked to 3D visual model • Built-in models with user-selectable parameters • Extensible via API

14. Catalogs • Maintain a collection of objects for reuse • Aircraft • Waypoints • User defined • DAFIF • Runways • User defined • DAFIF • Catalog is extensible

15. Catalog UIs • User-configurable catalogs for: • Aircraft models • Way points • Runways • Catalog interface for aircraft procedures

16. Aircraft Mission Modeler • Creating performance models • Modeling a multi-phase mission • Using the catalogs

17. Under the hood The following discussion of features and capabilities for Aircraft Mission Modeling includes information subject to pending patent applications

18. Under the hood • Aircraft Mission Modeler • Data-driven system • Designed to be used by non-experts • Analytic curves parameterized by well known aircraft performance values • Well known aircraft performance values • roll rate, bank angle, climb rate, airspeed • Building blocks for constructing complex missions • Sites • Procedures

19. Sites • Runways • Lat/lon values • Runway altitude • Runway heading • True/magnetic • Length • Catalog • Create & save • Use DAFIF data • Waypoints • Lat/lon • Catalog

20. Procedures • Takeoff • Choose runway heading • Departure Altitude • Departure point range • Use runway terrain

21. Procedures • Arc • Turn direction • Set altitude • Bearing • Arc radius • Turn angle

22. Procedures • Circular holding pattern • Turn direction • Level off maneuver • Bearing • Range • Number of turns • Time per turn

23. Procedures • Figure-8 holding pattern • Level off maneuver • Bearing • Range • Width • Length • Number of turns • Time per turn

24. Procedures • Racetrack holding pattern • Turn direction • Level off maneuver • Bearing • Range • Width • Length • Number of turns • Time per turn

25. Procedures • Landing • Approach altitude • Level off maneuver • Initial approach fix range • Glideslope • Use runway terrain

26. Point to point flight • Procedures employ point to point flight • Holding and Arc procedures • Fly from end of the previous procedure • To holding point • To start of Arc • Procedures over-fly waypoints • Specify heading at waypoint

27. Point to point flight • Position/heading to position/heading • Turns computed to minimize total heading change • Acceleration performance model • Determines bank angle for level, steady turns • Turns • Constant radius • First turn • Second turn • Turn radius • Turn bank angle • May vary

28. Translating a great arc aircraft • New aircraft from an existing great arc aircraft • Position and velocity vectors computed the same • Attitude window is used • Moving average algorithm

29. Performance models and procedures • Procedure/performance model exceptions • GtArc Procedure • Same logic as “old” great arc propagator • Basic Point to Point • Unconstrained behavior desired • Constant hold segment speed • Speed at which aircraft arrives at holding point • Specified time per holding turn

30. Earth surface height model • Major analysis capability improvements • Objects close to surface • WGS84 and MSL surfaces differ by tens of meters • AMM uses Mean Sea Level as altitude reference • WGS84 or MSL globe options • Set the globe surface to MSL!

31. DAFIF • Obtain DAFIF • Limited distribution • Versions 7 & 8 supported • DAFIF location • Tools–Options–File Find–DAFIF • Verify your DAFIF

32. Scripting and customization • Connect is supported • Connect is documented • COM is supported • Native implementation • All interaction is through COM interfaces • Custom user interfaces created with 4DX

33. Coordinate system • Current procedures • Generated in a flat earth coordinate system • Altitude is referenced to MSL • Mapping preserves great arc motion • Mapped to ECF coordinates • Extensibility model • Does not require a flat earth • Any coordinate system is supported

34. Level off maneuvers • Desired altitude unattainable • Vertical spiral • Override automatic LOM logic • Delay climb and descent

35. Vertical plane motion • Arbitrary climb and descent profiles • Smooth curve • Terrain Following • Same type of curve for vertical trajectory • Other vertical plane maneuvers • Constant radius arcs • Straight line segments

36. Climb and descent transitions • Performance models • Generate individual climb, cruise and descent profiles • “Stitched” together by procedures • Climb/descent angle • Intercepted using a constant radius arc • Trajectory follows the climb/descent angle • Aircraft changes velocity • Determined by acceleration performance model

37. Bank angle • Accounts for the total aircraft acceleration • Horizontal turn radius • Vertical plane acceleration • Speed • Climb angle

38. Validation & verification • Performed by Sensis Corporation • Generated 747-200 external performance model • BADA • Compared to flight trajectory generated by STK • Feedback • Implementation

39. Future • Business partnership • Aircraft performance model catalogs • New procedures and performance model categories • V/STOL - T/O, Hover and Landing • Carrier T/O and Landing • Formation Flight • Aerial Refueling • Air Intercept • Guided Missiles